FILE PHOTO: A Saudi Aramco employee sits in the area of its stand at the Middle East Petrotech 2016, an exhibition and conference for the refining and petrochemical industries, in Manama, Bahrain, September 27, 2016. REUTERS/Hamad I Mohammed /File Photo

The expansion into crude comes as Saudi Aramco is working to boost its valuation ahead of the planned listing of up to 5 percent of its shares on one or more international stock exchange next year, in what could be the world’s biggest initial public offering.

Saudi Aramco declined to comment.

Set up in 2012 to market refined products, base oils and bulk petrochemicals, Aramco Trading Company (ATC) will expand into crude to mainly feed international Aramco joint ventures like the Motiva refinery in the U.S. and S-Oil in South Korea, the sources said. They declined to be identified because they weren’t authorized to speak to media.

The Saudi Aramco [IPO-ARMO.SE] ventures abroad buy a certain portion of non Saudi crude for better economics and crude specifications, the sources said. Motiva’s 603,000-barrels-per-day (bpd) Port Arthur refinery in Texas became a subsidiary of Saudi Aramco on May 1 after Aramco and Royal Dutch Shell ended a 20-year refining partnership.

“Rather than that Motiva for example goes into the market and buy non-Saudi crude, Aramco Trading now can supply those barrels,” said one source with knowledge of Aramco’s strategy.

The unit of Saudi Aramco trades around 1.5 million barrels a day of refined, liquid chemical and polymer products, according to its website. ATC opened its first office abroad in Singapore in 2015 to market oil products and win new business for the parent company from Asia.

ATC has been trading higher volumes in derivatives markets since late 2014 as Saudi Arabia flipped from a net diesel importer to an exporter of the fuel as Saudi Aramco expands its global refining footprint.

Middle East oil producers are venturing into buying and selling oil to boost their incomes as a sharp drop in crude prices since mid-2014 has forced the industry to become more efficient and commercially focused.